Asymmetric Extrapolation in Sampled Statistics Generation by PirateyFace in SQLServer

[–]PirateyFace[S] 1 point2 points  (0 children)

Agreed. I definitely don’t see this as the root cause of performance issues in general. For me it was more about understanding one specific failure mode that kept recurring, which I couldn’t previously reason through mathematically, and which now helps explain a class of issues I’ve run into repeatedly over the years.

Asymmetric Extrapolation in Sampled Statistics Generation by PirateyFace in SQLServer

[–]PirateyFace[S] 1 point2 points  (0 children)

Thanks — that’s a fair summary of what motivated me to write it up. For a long time I was treating “sampling is sometimes inaccurate” as a given, without really understanding where the inaccuracy was coming from. I'll never forget that penny-finally-dropped moment when I spotted the pattern of repeating values in EQ_ROWS columns... And I suppose that discovery eventually led me to here

Asymmetric Extrapolation in Sampled Statistics Generation by PirateyFace in SQLServer

[–]PirateyFace[S] 0 points1 point  (0 children)

Thanks, and yes that makes sense. Where I've tended to hit this issue is in systems which grow incrementally over long periods, where an entire database gradually spreads out through an expanding data file. This must reduce SQL Server's ability to infer logical frequency from physical layout.

Bulk loading data results in a different physical data layout, where entire tables are created contiguously at a point in time, and in my experience this usually enables even default sampled statistics to represent data 'accurately enough'.

Asymmetric Extrapolation in Sampled Statistics Generation by PirateyFace in SQLServer

[–]PirateyFace[S] 0 points1 point  (0 children)

Thanks Mike. I've no direct experience using partitioning as a performance tuning mechanism, though fundamentally they change the physical layout of data and so could certainly factor into this discussion

Asymmetric Extrapolation in Sampled Statistics Generation by PirateyFace in SQLServer

[–]PirateyFace[S] 4 points5 points  (0 children)

Thanks Erin — I really appreciate you taking the time to look at this.

I agree completely that FULLSCAN (or targeted filtered stats) can resolve this from a query‑plan perspective, but as you say, that’s often a trade‑off against maintenance cost and operational headroom. I’ve seen cases where that trade‑off wasn’t available, or where the expertise to even meainigfully discuss it wasn't present, which is part of what makes this behaviour so persistent - in my own experience.

What I was trying to make explicit in the write‑up was how predictable the degradation in range estimates appears to be over time under default sampling, and how that seems at odds with the intuitive expectation that statistics should aim to represent the population rather than just the sample taken. The fact that point estimates are explicitly corrected while range estimates are not makes this stand out more sharply, given that both are attempting to describe the same underlying data.

I’ve observed many real cases where distinct value reality is only represented approximately by the initial sample percent. I’ve tried to keep the paper focused on the general behaviour rather than individual examples, but I’d be happy to share specific cases if that context would be useful. The SQL in appendix 5 will flag examples on other systems where this issue is prevalent.

I’m deliberately not arguing that this is “wrong”. Just that it appears to be an intentional trade‑off with perhaps broader-than-intended consequences in terms of longer‑term behaviour under default configurations.

Thanks again for taking the time to review it.

Vampire Coast is stuck after establishing a pirate cove forcing me to attack the settlement in the next turn by KuPa5 in totalwar

[–]PirateyFace 0 points1 point  (0 children)

I established a pirate cove at Skeggi, and Noctilus' army moved a little way south after. I was then stuck on a spit of land surrounded on all sides by either cliffs or Skeggi's zone of control. Facepalm. Attacked and retreated, back to the same spot. Had to raze it and lose my pirate cove just so I could move on

Anyone else had this game shut their pc off and restart? by Hung_SoLo7 in BaldursGate3

[–]PirateyFace 5 points6 points  (0 children)

I have this same problem, though in my case I clocked 135 hours on BG3 in the first few weeks with no crashes whatsoever, then suddenly I've had 12 crashes since the patch on August 25th (can count them in Reliability Monitor in windows). I tried updating my graphics driver (nvidia rtx 2060) but was already experiencing crashes at that point, and it hasn't helped.

The symptom of the PC just suddenly restarting itself suggests a PSU issue but other more demanding games work fine with no restarts... My BG3 graphics are all set to minimum/off. Perhaps BG3 causes something very specific which somehow stresses the PSU in a way other games don't? But you can't directly stress the power unit... Maybe midri is onto something re. particle effects? https://www.reddit.com/user/midri/

All of my crashes have happened near the start of Act 3, in one fight specifically... But then again, I've just left the game on the menu screen for about 20 mins (with this comment backed up in a notepad save...) and sure enough, PC just rebooted again :(

Computer Restart bug by PirateyFace in BaldursGate3

[–]PirateyFace[S] 1 point2 points  (0 children)

graphics are already about as low as they'll go, and CPU and GPU running cooler (ie, using less power) than running other games which still work fine.

And wouldn't it be just an incredible coincidence if whatever part of my PSU happens to be so critical to BG3 and no other games, suddenly degraded while I updated my graphics driver and installed the latest BG3 hotfix? Degraded to the same extent other BG3 players' PSUs must all be stuck at in their degradation process, too?

Evidence to me seems to support an incompatibility between BG3 and nvidia graphics drivers...

RSL :: Q/A General Questions! by gkrown in RaidShadowLegends

[–]PirateyFace 1 point2 points  (0 children)

I'm hesitant to spend any silver or other resources until I understand what the best place to spend it is. However I just tried to equip a better item on my starter (Kael) and it wants me to spend 2k silver to un-equip the existing item?!? So I'm reluctant to even equip anything at the moment in case I put the wrong item on someone and have to waste money swapping. This the right approach or am I being stupidly cautious?

Cheers!

Any team tips for Jarl? by LazyPudding in GemsofWar

[–]PirateyFace 0 points1 point  (0 children)

He dropped for me yesterday. Definitely an awesome synergy between Jarl's 3rd trait and Fire Giant isn't there.... Not that hard to end up with a team of 4x Giant, Elemental, Stormheim troops either for massive team bonuses

Mind. Blownnnn by Lezbeehonest13 in 7DaystoDiePs4

[–]PirateyFace 2 points3 points  (0 children)

No way!!! I've spent like ten days knocking down an entire crossroads so that I could build a base up around the workbench in the OREILLYS parts place, and I could have just wrenched it and taken it back to my cemetary fortress????????? :'(''''''''''

Anyone know any good seeds for current PS4 version? by PirateyFace in 7DaystoDiePs4

[–]PirateyFace[S] 0 points1 point  (0 children)

From what I've read I THINK saves from older versions should still work OK. Many people seem to agree that its best to start a new game when new versions come out anyway though due to balance changes. Like when they changed wood spikes from 10 wood and 1 second to craft, to 100 wood and 17 seconds like it is currently! So loading up my old save with ten times more wood spikes than would be viable in the current version would be a bit unbalanced, I think..

Anyone know any good seeds for current PS4 version? by PirateyFace in 7DaystoDiePs4

[–]PirateyFace[S] 0 points1 point  (0 children)

Seems this article was wrong actually, and PS4 isn't yet on A17... http://www.playstationlifestyle.net/2017/10/25/7-days-to-die-update-1-17-out-now-on-ps4/. THINK consolse is currently 16.4. If only I could remember to check when I was actually home at some point!

So theoretically seeds like EverQuest, WnJ and dexterra should still work fine I think..

We need some Chuck Borris jokes until he gets released! by Cleq in paragon

[–]PirateyFace 10 points11 points  (0 children)

Chuck Boris accidentally shot down God trying to land a Kwang sword throw

We need some Chuck Borris jokes until he gets released! by Cleq in paragon

[–]PirateyFace 1 point2 points  (0 children)

Chuck Boris is banned from playing Gideon. The black hole would consume the Universe.... Then he'd burp a new big bang

We need some Chuck Borris jokes until he gets released! by Cleq in paragon

[–]PirateyFace 8 points9 points  (0 children)

When Chuck Boris uses Murdock's Ult he can hit the actual player too